This invention relates to the field of computer networks and, in particular, to an automated method of Internet address management for an Internet Protocol (IP) routed network.
TCP/IP (Transmission Control Protocol/Internet Protocol) is fast becoming the dominant communication protocol in the field of computer networks and telecommunications. The TCP/IP protocol divides files that are to be transmitted across a network into small data packets. The small packets are transmitted, and possibly routed through numerous networks, and then reassembled once they arrive at the intended receiver of the transmission. The TCP/IP protocol defines what the packets look like, what information they must contain, how they are to be transmitted, received and reassembled. TCP/IP is the standard protocol used by computers connected to the Internet that allows Internet users to communicate world-wide even over diverse transmission networks. TCP/IP is also used in local area networks (LAN), wide area networks (WAN), and other computer networks even if they are not connected to the Internet. Generally, these networks are referred to as "IP routed networks."
The TCP/IP protocol utilizes IP addresses to identify individual computers, peripheral devices or users (collectively referred to as "nodes") connected to an IP routed network. An IP address includes four numerical parts often referred to as "bytes," or "octets," separated by periods (that is, "octet1.octet2.octet3.octet4"). Each octet represents an 8-bit binary number that can have a numerical value ranging from 0 to 255 (0 and 255 are typically not used because they are reserved). Thus, for example, one IP address might be 56.1.250.1 while a second IP address might be 200.10.1.100.
Every IP address includes a network portion to identify the network and a node portion to identify a particular node of the network. There are three main classes of IP addresses. The class A IP address consists of one octet (octet1) representing the network portion and three octets (octet2 to octet4) representing nodes (also referred to as "hosts") of the network. To help route information quickly, the upper four bits of octet1 are used to distinguish between the three classes. Accordingly, the class A IP address range is limited to 127 available networks (octet1 having a value between 1 and 127). Although there are only a few class A network addresses, each class A network can have over 16 million node addresses. The class B IP address consists of two octets (octet1 and octet2) representing the network portion and two octets (octet3 and octet4) representing nodes. There are about 65 thousand class B network addresses available (octet1 having a value between 128 and 191) with each class B network having over 65 thousand nodes. The class C IP address consists of three octets (octet1 to octet3) representing the network portion and only one octet (octet4) representing nodes. There are approximately 2 million class C network addresses (octet1 having a value between 192 to 223) with each class C network having 254 nodes. Two other classes, D and E, which are not discussed further utilize the remaining available addresses (that is, octet1 having a value greater than 223).
Since people found remembering the numbers in an IP address assigned to individual computers, or other equipment, extremely burdensome and difficult, a Domain Name System (DNS) was created in 1984. DNS is a system wherein IP addresses are mapped to names. DNS names are divided into domains and are constructed hierarchically in an inverted tree structure. FIG. 1 illustrates an exemplary structure of a domain name space wherein each "leaf" on the tree 10 represents a domain or subdomain. Every domain, such as "mci.com" (which is actually a subdomain of the domain "com"), stores local host information about its domain in a local name server. The Internet, for example, uses several huge DNS servers to coordinate the local name servers and provide access to the Internet.
A host named "node1" residing in the "mci.com" domain, for example, would have the host name (also referred to as a "domain name") "node1.mci.com". That is, a host name is made up of labels assigned to each leaf on the path from the root of the tree to the host. A DNS database is responsible for cross-referencing the host to its corresponding IP address. Each time an Internet user, for example, attempts to access a host name such as "node1.mci.com," for example, a DNS name server uses the database to translate the name into its assigned IP address.
When a new host or node is added to an existing network, both a host name and an IP address must be assigned to that host and entered into the DNS database. Generally, networks can be divided into subnetworks or "subnets." The term "subnet" as used herein refers to a group of terminals or computers within a network. Assuming, for example, the network has a class B address, the octet3 and octet4 portions of the IP address could be used to address the subnet of that network. That is, the class B network could have 254 subnets (octet3) each having 254 addressable nodes (octet4). If the network has a class A address, its class B and C portions (i.e., octet2, octet3 and octet4) could be used to address subnets of that network. To assign a new host name/IP address to a subnetwork, there must be an available subnet IP address within the address space reserved for the requested network. Otherwise, a new subnet address space must be created for that network.
Currently, when a DNS administrator receives a request to create a new host name and an associated IP address, the administrator must manually inspect the DNS database to determine if there are any available addresses in the address space reserved for the requested subnet. The administrator must then ensure that both the newly created IP addresses and host names are unique, since duplicate addresses or host names would cause havoc to the network. If there is no available subnet addresses for the requested subnet, the administrator must start a new subnet address space within the IP address range of the network. Once the host name/IP address assignment is completed and entered into the local DNS database, the information will be passed to a higher level DNS server where a process known as "resolution" is performed to ensure the validity of the host name and IP address (when the network is connected to a larger network such as the Internet).
Currently, the DNS assignment steps of inspection of the DNS database and the creation of host names and IP addresses are all being performed manually. This means that an administrator of the network must receive a request for a host name/IP address assignment, find an available IP address for the requested subnet, and create a host name (or implement the requested host name) that has not already been assigned to another requester. This process takes an undesirable amount of time and has a high potential for human error. In addition, since DNS administrators often receive requests in batches (that is, more than one new name/IP address assignment is requested at a time), the above tasks become much more complicated and even more time consuming. The database must be inspected to find multiple available IP addresses which may be spread throughout the ever increasing database. Sometimes, an administrator may determine that creating a new subnet address space is easier than hunting through the database to find available addresses. Although this ensures that unique IP addresses are being created, this wastes available addresses in the original subnet address space.
As stated above, the administrator must also ensure that the new host name is unique. In addition, some organizations place restrictions or have required formats for creation of host names used in their network. For example, an organization may want a city or state name incorporated into the host name. That is, if the host named nodel resided in Durham, N.C., for example, the organization may want the host name to be "durhnode1.mci.com." Thus, placing an additional burden on the administrator to ensure validity as well as uniqueness of the new host name. Errors resulting from the manual inspection, creation and entry of the new host name/IP address assignments frequently occur. These errors can lead to network problems and poor customer service (if the DNS services are being provided for a customer's network). In addition, the process is too time consuming even when performed error free.